1. Field of the Invention
The present invention relates generally to helicopters and, more particularly, to skid landing gear that are quickly removable using expandable bushing fittings to facilitate compact storage of helicopters.
2. Description of Related Art
Military and commercial helicopters are often transported by fixed-wing transport planes to new operational sites. Since cargo space is always at a premium, these helicopters must in most cases be partially disassembled to fit into the cargo holds of the delivery vehicles. Especially when the helicopter is to be used for military purposes, it is desirable that the helicopter be easily and quickly reassembled at the destination, preferably without the aid of heavy or complex equipment which must also be shipped to the reassembly location. Although the same urgency is usually not prevalent for civilian helicopters, a capability for quick and convenient assembly and disassembly would no doubt be appreciated by civilian operators.
FIG. 1 illustrates a conventional pair of skid landing gear 15 for use with a helicopter. The pair of skid landing gear 15 comprises two skids 17 and 19 having abrasion shoes 21 and 23, respectively. These skids 17 and 19 further comprise steps 28 and 30. The two skids 17 and 19 are joined by an aft crosstube 33 and a forward crosstube 35. Fittings 37 and 39 join the aft crosstube 33 to both the skid 17 and the skid 19, and fittings 41 and 43 join the forward crosstube 35 to both the skid 17 and the skid 19. Dampers 50 and 53 are positioned at the interface between the aft crosstube 33 and the two skids 17 and 19.
The pair of skid landing gear 15 is joined to the fuselage of a helicopter (not shown) via an aft fuselage fitting 58, an aft saddle point fitting 60, a forward saddle fitting 62, and a forward fuselage fitting 64. The aft fuselage fitting 58 and the aft saddle point fitting 60 secure the aft crosstube 33 to the fuselage of the helicopter, and the forward saddle fitting 62 and the forward fuselage fitting 64 secure the forward crosstube 35 to the fuselage of the helicopter.
FIG. 2 illustrates a closeup view of the forward saddle fitting 62. The forward saddle fitting 62 comprises two tension bolt apertures 71. These tension bolt apertures 71 accommodate tension bolts (not shown), which are carefully torqued into the bottom of the helicopter fuselage to thereby secure the forward crosstube 35 to the helicopter. Similarly, as illustrated in FIG. 3, the aft saddle point fitting 60 comprises two tension bolt apertures 74 for accommodating two tension bolts. These tension bolts are fed through the tension bolt apertures 74 and into the fuselage of the helicopter, and are then carefully torqued. The process of securing the pair of skid landing gear 15 to the fuselage of a helicopter can be cumbersome.
Although the prior art has recognized some of the advantages associated with attaching wheels to the pair of skid landing gear 15, the prior art has not endeavored to replace the pair of skid landing gear 15 with a pair auxiliary crosstubes having low-profile wheels attached thereto to thereby facilitate compact storage of the helicopter. U.S. Pat. No. 5,060,886 to Davis et al. discloses an auxiliary wheeled landing gear that may be substituted for a baseline skid landing gear on a helicopter. This substitution is intended for those operators who desire to taxi their helicopters on the ground in order to avoid aerial taxiing or the inconvenience of using dolly wheels and a tow bar. The wheels, however, are not low profile, and once installed, the wheels do not appear to be readily removable. The installation of the wheels according to this patent appears to incorporate standard aircraft bolts and nuts. U.S. Pat. No. 5,109,580 to Canus discloses an assembly of clamps and fittings for attaching a platform to a helicopter's skid landing gear. This patent, however, does not address the concern of providing readily attachable and detachable low-profile wheels as a substitution for the skid landing gear of a helicopter.